Grinding machine



y 1943- G. T. MUSKOVIN ETAL GRINDING MACHINE Filed Nov. 12, 1941 3Sheets-Sheet 1 GEURGE T/Vusn av/N JaH/v [EHRS/DE July 13, 1943.

G.-T. MUSKOVIN ETAL 2,324,266

GRINDING MACHINE 3 Sheets-Sheet 2 Filed NOV. 12, 1941 III/1122a./7III/IIIIIIIIA S50E55 TML/sKov/N JOHN J? SHE'S/0E Mum W J y 1943- a.T. MUSKOVIN arm. 2,324,266

GRINDING MACHINE Filed Nov. 12, 1941 a Sheets-Sheet s gwuwvkw GEORGETMusKa VIN J H/v 1. EHRS/DE Mwm Patented July 13, 1943 D 2,324,268GRINDING monmn George T. Mnskovin, Worcester, and John I. Gar-side, WestBoylston, Masa, assignors to- Norton Company, Worcester, Mass., atcorporation of Massachusetts Application November 12, 1941, Serial No.418,786

6Claims.

The invention relates to grinding machines, and more particularly to agrinding machine for producing a partial cylindrical surface.

One object of the invention is to provide a simple and thoroughlypractical grinding machine for producing a partial cylindrical surface.Another object of the invention is to provide a work supporting andindexing mechanism for grinding a partial-cylindrical surface on a workpiece. A further object of the invention is to provide an oscillatablework supporting apparatus in which the work support is automaticallyindexed by and in timed relation with the work reciprocating movementrotarily to index the work piece after each reciprocation thereof. Etherobjects will be in Part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction,combinations of elements, and arrangements of parts, as will beexemplified in the structure to be hereinafter described, and the scopeof the application of which will be indicated in the following claims.

In the accompanying drawings in which is shown one of various possibleembodiments of the mechanical ieatures of this invention,

1 is a front elevation of a grinding machine embodying the invention;

2 is a fragmentary front elevation, on an enlarged scale, of the worksupporting and indexing mechanism, having parts broken away and otherparts shown in section to more clearly illustrate the structure thereof;

Fig. 3 is a fragmentary sectional view, taken approximately on the line3-3 01' Fig. 1, showing the work supporting and indexing mechanism inend elevation;

Fig. 4 is a fragmentary cross-sectional view, on an enlarged scale,taken approximately on the line 4-4 of Fig. 2; and

Fig. 5 is a fragmentary plan view, on an enlarged scale, of the workholder and work piece, together with a portion of the indexingmechanism.

A grinding machine has been illustrated in the drawings comprising abase i having a longitudinally movable work table II supported on a flatway i2 and a V-way E3 on the base it. A grinding wheel i is rotatablysupported on a transversely movable wheel slide 16 which is supported ona vertically movable slide l'l carried on an upwardly extending column!8 of the base to. The vertically movable slide I! is arranged tor amanual adjustment to position the periphcry of the grinding wheel I5relative to the surface of the work piece which is mounted on thetableII in a manner to be hereinafter described so as to grind a surfacethereon to the required extent.

This mechanism may comprise a manually 0 erable feed wheel 29 which ispreferably of a type similar to the well-known feeding mechanism, suchas shown in the expired U. S. patent to Norton, No. 1,108,779 dated Aug.25, 1914. The manually operable feed wheel 20 is connected to rotate agear 2| meshing with a gear 22. The gear 22 is formed with an internalthread with engages or meshes with a feed screw 23, the lower end ofwhich is fastened to the vertically movable slide i'l. By rotating thefeed wheel 20, the operator may raise or lower the grindingwheel i5relative to the table ii as desired.

Table reciprocating mechanism The table I! is arranged so that it may bereciprocated by a suitable power operated mechanism to carry the workbeneath the operative face of the grinding wheel iii. In the preferredform, the reciprocating mechanism comprises a fluid pressure systemincluding a cylinder 25 mounted within the base iii. A piston 26 isslidably mounted in the cylinder 25 and is connected by a piston rod 2?to a depending bracket 28 on the under side of the table II. The base I0is provided with a fluid reservoir 30 from which fluid is pumped througha pipe 3i by means of a motor driven pump 32. The pump 32 forces fluidunder pressure through a pipe to a reversing valve (not shown). Thereversing valve is arranged to direct fluid under pressure eitherthrough a pipe 35 to a cylinder chamber 36, or through a pipe 31 into acylinder chamber 38. A table actuated reversing lever 39 is pivotallysupported on the front of the machine base and is arranged to beactuated by means of a pair of adjustable table dogs 40 and 4| which areadjustably supported by a T-slot 42 formed in the front edge of thetable ll.

A stopand start valve (not shown) is arranged to be actuated by means ofa manually operable start and stop lever 15 on the front of the machinebase. A speed control valve is provided by a control knob 53 alsomounted on the front of the machine base ID. The details of thehydraulic table reciprocating mechanism have not been fully illustratedin the present case since they are not considered to be a part of thepresent invention. This hydraulic table reciprocating mechanism isidentical with that shown in the prior U. S. patent to Carl G. Flygareand as N sg gg g U. 8. Patent No. 2,022,542 above mentioned towhichreferencemaybehadfor detailsofthis mechanism.

In order to attain the main obiect of this invention, an oscillatablework supporting mechanism is provided whereby the work piece may beindexed through a partial rotation after each reciprocating movement ofthe table to resent a different portion of the work piece to thegrinding wheel whereby a partial cylindrical surface on the work piecemay be ground to the desired and predetermined extent. A work supportingfixture II is mounted on the upper surface of the table II. The fixtureII is provided with a pair of spaced upwardly projecting arms ll and I!which serve as a support for an oscillatable work supporting cradle 82.The cradle II is provided at its opposite ends with oppositely extendingtrunnions l4 and 5', respectively. The trunnions I4 and II are supportedby antifriction bearings It and I! which are in turn supported in thearms II and II, respectively, or the work supporting fixture II. Thework supporting cradle It is provided with a plane work supportingsurface it.

A work piece II is arranged to be supported on the surface II. The workpiece ll is provided with four integrally formed projecting lugs ll, 62,t2 and t4 having holes therein which are arranged to mate with aplurality of locating pins or studs la, 62a, its and a fixed on thecradle 53. The work piece I is held in position on the work supportingcradle II by means of a pair of spring-pressed piungers I and It. Theplungers l5 and It are supported in projecting b'osses U1 and 82 formedintegral with the work cradle 53. A pair of binder or clamping screws 82and II are provided for clamping the plungers I and I in position toprevent lifting of the work piece I during a grinding operation. Thework piece 6| has a partial cylindrical surface extending between thebosses ti and 3 (Fig. 4) which is to be ground to the desired andpredetermined extent. The grinding Operation is accomplished by means ofan indexing movement of the work supporting cradle 52 intimedrelationship with the longitudinal reciprocatory movement of the worktable i I. r

A suitable mechanism is provided for rocking the work supporting cradle52 on its trunnions l4 and ii. This mechanism may comprise a bevelledgear it which is mounted on the end of the trunnion II. The bevel gear80 meshes with a bevel gear II which is keyed to a rotatable shaft I2.The shaft if is rotatabiy lournalled in bearings I3 and N which areformed integral with a bracket II. The bracket II is in turn fastened tothe table I I.

An arm I is keyed to the shaft l2 and sup ports at its outer end aroller or cam follower II. A cam ll, preferably of a heart-shapeddesign, is keyed to a rotatable shaft II. The shaft 82 is iournalled inbearings ll and II which are fixedly supported on the table II. Amanually operable hand wheel 92 is mounted on the outer end of the shaftII, by means of which the shaft plurality of clamping screws 2|. I! andill. clamping screws II, II and Ill pass through elongated slots formedin the bracket II and are screw threaded into the base IO. It will bereadily appreciated from the foregoing disclosure that the bracket 21together with the pawl It maybe adjusted vertically to position theoperative'end of the pawl II in the desired position relative to theratchet wheel II. The ratchet pawl 00 is pivotally supported by a studII I An adjustable stop screw ll! serves to limit the rocking movementof the pawl N in a clockwise direction. A

. tension spring I" is interposed between the pawl It and the bracket llandserves normally to maintain the pawl l in engagement with the stopscrew I02. a

When the table il moves toward its extreme left-hand end position. thepawl 00 engages one of the teeth of the ratchet wheel I! and continuedmovement of the table Ii toward the left serva to rotate the ratchetwheel II to transmit a partial rotation through the cam and gearmechanism above described to produce a partial rotary motion of the workpiece Cl.

A holding pawl I is pivotally supported on a stud ill which is in turnsupported in fixed relation with the table II. The pawl III ismaintained in the position illustrated in Pig. 2 under the influence ofgravity and serves to prevent a clockwise movement of the ratchet wheel2!. The holding pawl ll may be swung in a clockwise direction to aninoperative position, in

which position the parts may be readily rotated by rotation of themanually operable hand wheel II. The ratchet wheel 08 and pawl It arearranged so that the ratchet wheel may be readily and manually rotatedin a counterclockwise direction during which the pawl 26 swings underthe tension of the spring ill.

The grinding operation is preferably started when the work cradle I2 isin broken line position is (Fig. 3). In this position of the parts, thework table Ii is reciprocated to traverse the work piece OI beneath theconcave peripheral face of the grinding wheel II. After one completereciprocation of the table II, the ratchet wheel II engages the pawl IOand indexes the cradle II in a counterclockwise direction (Fig. 3)through a partial revolution to prwent a new portion of the work piecetothe grinding wheel I on the next reciprocation therebeneath. Theautomatic indexing of the work supporting cradle II and work piece Icontinues until the work cradle assumes the broken line position 53b(Fig. 3), in which position the wheel H has ground the desired partialcylindrical surface on the work piece 50. A pair of end thrust screws Hand Ill are provided to engage the end faces of the work piece 50 to aidin holding it against endwise movement on the work cradle 53 during thegrinding operation.

A truing tool H2 is mounted on the upper portion of the cradle 53 (Fig.2). when it is desired to true the periphery of the grinding wheel 15 toa concave shape, the truing tool 2 is raised upwardly so that thecutting point of the truing tool coincides with an element of thesurface to be ground. In this position of the parts, the holding pawl Iis moved to an inoperative position and the cradle 53 oscillated bymanual rotation of the hand wheel 92 to oscillate the truing tool H2 inan arcuate path to true the operative peripheral face of the grindingwheel to the desired and. predetermined extent. During the truingoperation, lf-desired, the grinding wheel l5 may be adjusted downwardlyby manipulation of the vertical feed wheel 20.

The operation of this improved grinding apparatus will be readilyappreciated from the foregoing disclosure. A work piece 60 is mounted inposition on the work supporting cradle 53 in a manner hereinabovedescribed and the cradle 53 is rocked to position 53a (Fig. 3) by manualrotation of the wheel 92. Assuming the grinding wheel l5 has beenpreviously trued, the reciprocatory movement of the table ii is startedbyactuation of the stop and start lever 42 and the work piece tiltogether with its support and the table ll are traversed toward theright through the desired stroke to traverse the work piece beneath thegrinding wheel l5 so that a path extending its entire length is ground.

After one complete reciprocation of the table ii, the ratchet wheel 95engages the pawl 96 and rotates the ratchet wheel in a counterclockwisedirection and indexes the work supporting cradle 53 and the work piece60 so as to present a new portion of the partial cylindrical surfacebeing ground into alignment with the operative face of the grindingwheel i5 before the work piece moves into operative grinding engagementwith the wheel i5 on its next reciprocatory stroke. After eachsucceeding reciprocatory stroke, an indexing movement is imparted to thework cradle 53 and the work piece 60 in a manner above described untilthe work cradle together with the workpiece moves into the broken lineposition 53b (Fig. 3), in which position the partial cylindrical surfacehas been ground to the desired extent. The ground Work piece may then beremoved from the machine and a new work piece inserted thereinstead forthe next grinding operation.

The apparatus shown in Figs. 1 and 2 illustrates a work cradle 53arranged to support one work piece 60. t will be readily appreciatedthat, if desired, the fixture 50 and the work cradle 53 may be made muchlonger so as to support a plurality of work pieces 60 in position for asimultaneous grinding operation. In such a case, the work pieces arearranged in alignment on the cradle 53 so that the axes of the partialcylindrical surfaces to be ground coincide. In this position, it will bereadily appreciated that two or more work pieces may be readily ground,it being merely necessary to adjust the table dogs 40 and 4| tofacilitate a longer grinding path.

It will thus be seen that there has been provided by this inventionapparatus in which the various objects hereinabove set forth togetherwith many thoroughly practical advantages are successfully achieved. Asmany possible embodiments may be made of the above invention and as manychangesmight be made in the embodiment above set forth, it is to beunderstood that all matter hereinabove set forth or shown in theaccompanying drawings is to be interpreted as illustrative and not in alimiting sense.

1. In a grinding machine having a base, a longitudinally reciprocabltable, a wheel slide thereon, a rotatable grinding wheel on said slidehaving a concave operative face and having its axis arranged normal tothe reclprocatory movement of said table, means to reciprocate saidtable; an oscillatable work support pivotally mounted on said tablehaving its axis arranged parallel to the movement of said table, meansto support a work piece thereon having a partial cylindrical surface tobe ground, and an indexing mechanism for said work support including acam actuated gear mechanism which is actuated by and in timed relationwith the table movement rotarily to index said work piece to index thework piece by an amount substantially equal to the width of the grindingwheel.

2. In a grinding machine having a base, a longitudinally reciprocabletable and an adjustable wheel slide, a rotatable grinding wheel on saidslide having a concave operative face and having its axis arrangednormal to the reciprocatory movement of said table, means to reciprocatesaid table, a pivotally mounted work support on said table having itsaxis arranged parallel to said table movement, means to support a workpiece thereon having a partial cylindrical surface to be ground, anindex mechanismincluding a cam actuated gear mechanism rotarily to indexsaid work support, and means actuated by and in timed relation with thereciprocatory movement of said table to actuate said indexing mechanismafter each complete reciprocation'of said table to index the worksurface by an amount 1 less than the width of the grinding wheel so asto present a different portion of the work surface to the grinding wheelon each reciprocatory movement thereof so as to grind a predeterminedcontinuous partial cylindrical surface thereon.

3. In a grinding machine having a base, a longitudinally reciprocabletable and a vertically and transversely adjustable wheel slide, arotatable grinding wheel on said slide having a concave operative faceand having its axis arranged normal to the reciprocatory movement ofsaid table, means to reciprocate said table, a pivotally mounted worksupport on said table having its axis arranged parallel to said tablemovement, means to support a work piece thereon having a partialcylindrical surface to be ground, an index mechanism including gearingrotarily to index said work support, a rotatable cam and a follower toactuate said gearing, and means including a pawl and ratchet mechanismactuated by and in timed relation with the reciprocatory movement ofsaid table to actuate said cam and gear-indexing mechanism after eachcomplete reciprocation of said table so as to present a differentportion of the work surface to the grinding wheel on each reciprocatorymovement thereof so as to grind a predetermined continuous partialcylindrical surface thereon.

4. In a grinding machine as claimed in claim 1, the combination with theparts and features therein specified, of an indexing mechanism includingeorinlrotorilytoindexnidmkmport,meangmcludingecemendoiollowertoactmteeeid eoringentchetwhoeltorotete ntd com. and a pawl edimtehlymounted on nidbuewhiohilarnnledtommdactmtenidntchetwheeleltereeeheompleteneiprocstorymovementotleidtohletocauleswtiolrotatlonottheworknwporttoprelentediilermtportionoitheworkpleoetotheopentiveieeeoltherindingwheelonmcoeesiverecipmcotoryltrokeetherebetween.

tlnogrindinsmochineuchimedinchimi, the combination with the port; andieatui-ea therein specified. of an indexin: mechanism inciudin: [eatingrotarily to index llld work support, u rock erm to rotote said 8m, I.101- lower on said rock arm, a rotatable camehzuedhynidiollowenendepewimdntcheteetmtedhylndintimedrelhflonwithleidtehieredproeotiontoindezuidmmoi'ttlnlgrmdingmachineuehimedincieimi, the with the put: end teotm'uthereinopeciMoi'mMmechmimtor said work support includin; ntable-actuated com-controlled mechanism whereby the worksupportinlybeinorementenylndhitermittentlyindexedoftei-eochcompletereciprocetlonoithe tebiemdemnmmiiyoperabiehendwheelior ectunting saidindexinlmechanilmtohdlitote a manualadjustment of said workmpport.

(mom: '1'. movm. JOHN I. omamn.

